//处理数字的工具函数
export function getRandomNumber(num: number) {
  return Math.floor(Math.random() * num);
}
export function mask(str: string, begin: number, end: number, char: string) {
  const fstStr = str.substring(0, begin);
  const scdStr = str.substring(begin, end);
  const lstStr = str.substring(end, str.length);
  return fstStr + scdStr.replace(scdStr, char) + lstStr;
}
